New method for determination of shear properties of wood

A new method for the determination of shear modulus and shear strength is presented in this study using a shear or picture frame. A shear frame in accordance with DIN SPEC 4885 is in other fields, such as fibre reinforced composites, state of the art. Here, a square test specimen with recessed corners is held in the shear frame and subjected to a quite uniform shear deformation state. To determine the shear modulus and the shear strength, tensile load acting on the shear frame and the associated shear strain are measured. This method has the advantage of simultaneous determination of the shear modulus and the shear strength. Thin square wooden plates of European beech ( Fagus sylvatica L.) were tested in all anatomical directions. The results show good accordance with literature values. The highest values of shear modulus and shear strength were yielded for the LR plane, followed by the values in the LT plane. The tests in the RT plane clearly resulted in the lowest values.